Are you sure you’re well-prepared for your next job? Read on to study some of the most common AWS VPC Interview Questions that you should be able to answer.
If you’re planning to achieve career advancement in cloud technology, you just can’t ignore Amazon Web Services. Among the various AWS services, Virtual Private Cloud (VPC) is becoming increasingly popular these days.
If you’re serious about pursuing a career in AWS, you’ll need to know the essentials of VPC, which should give you an edge over the competition in the job market.
However, being able to answer these questions won’t be enough. You’ll also need to have an AWS certification in hand to find your dream job. We truly hope that this guide helps you fetch the job of your choice.
The following AWS interview questions on VPC have been compiled with recruiters’ mindset and preferences in mind:
AWS VPC interview questions and answers
1. What is AWS VPC?
The Amazon Virtual Private Cloud (VPC) is a service that enables you to launch AWS resources in a self-defined virtual network.
This means that the virtual networking environment you’re working on will be in your complete control, including the ability to select your own network gateways and IP address range, the formation of subnets, and the configuration of route tables.
If you wish to control the AWS cloud through your corporate data center, you may even connect your data center with VPC through the hardware VPN connection.
2. What are the Components of Amazon VPC?
The AWS VPC consists of a number of networking components that include:
- Subnets: It’s a network within a network that makes networks efficient by enabling traffic to travel a short distance without having to pass through unnecessary routers to reach the destination.
- VPC peering: A networking connection between multiple VPCs that allow you to privately route traffic between them.
- Elastic network interface: A virtual network card or interface that can be attached to an instance in a VPC.
- NAT: Network address translation (NAT) works as a gateway that allows instances in a private network to connect to services outside your VPC. However, external services won’t be able to establish a connection with those instances.
- Route tables: Contain a set of rules to guide network packets from your gateway or subnet need to go to reach their destination.
- VPC endpoints: An easily accessible, redundant, and horizontally scaled virtual device that allows for uninterrupted communication among EC2 instances in your VPC and other applicable AWS services without causing bandwidth constraints and availability risks on your network traffic.
- Internet gateways: VPC component that enables your VPC to effectively communicate with the internet.
- Elastic IP addresses: A public, static IPv4 address that can be associated with any network interface or instance in any VPC in your account.
3. Why Should I Use AWS VPC?
By leveraging AWS VPC, you should be able to build a virtual network in the AWS cloud without investing in any physical data centers, VPNs, or hardware.
Plus, you possess full authority over your network space, including how your Amazon EC2 and network are exposed to the internet.
Moreover, you have the privilege to manipulate and improve the security options in AWS VPC. This allows for more granular access between the Amazon EC2 instances in virtual networks.
4. How is AWS VPC Different from AWS EC2?
When you use AWS VPC, your instances will run in a logically alienated virtual private network from your AWS account. In contrast, when using AWS EC2– Classic, your instances will run in a single flat network that you share with other clients.
5. What is the Role of an Amazon VPC Router?
The function of an amazon VPC router is to allow for efficient communication between Amazon EC2 instances in subnets and those in other subnets that share the VPC.
Plus, it allows virtual private gateways, internet gateways, and subnets to communicate with each other. While you can’t obtain network usage data from the router, you can use Amazon CloudWatch to access those stats from your instances.
6. How Many VPCs, VPNs, Subnets, and Gateways Can I Create at Maximum?
The creation of those items is certainly subject to specific limits. At most, you can create five VPCs in a single region. If you wish to increase the limit, the internet gateway will also need to be proportionately increased.
The maximum limit for VPNs, elastic IP addresses, NAT gateways, and internet gateways is also set to five. The limit for the number of subnets is 200 per VPC.
Besides, customer gateways have a limit of 50 per region.
7. What are Security Groups?
The purpose of a security group in a VPC is to efficiently manage traffic for one or more instances. The group serves as a virtual firewall that will control inbound and outbound traffic for various EC2 instances.
To control the traffic in associated instances, you can manually define rules for each security group. Security groups in your AWS console should be located in both EC2 and VPC sections.
Security groups, by default, allow outbound traffic. Likewise, you can add rules to allow inbound traffic. While you can define “allow” rules, you cannot set up “denial” rules in an attempt to restrict specific security permissions.
Besides, you can always alter the rules you’ve defined for a security group whenever you want. Whatever changes you make will be implemented instantly.
8. How Do I Set Up a Custom VPC?
Follow these steps to build a custom VPC:
- Step 1: Set up a virtual private cloud (VPC)
- Step 2: Formulate subnets
- Step 3: Develop an internet gateway
- Step 4: Connect the new internet gateway with your VPC
- Step 5: Set up a new Route Table
- Step 6: include the internet gateway in the Route Table as a route
- Step 7: In the subnet association of the Route Table, include a subnet
- Step 8: For the private subnet, develop a database server, while for the public subnet, formulate a web server.
- Step 9: For the NAT, create a fresh security group.
- Step 10: Add inbound rules for HTTPS and HTTP to allow the traffic inflow from the IP of private subnets.
- Step 11: Set up a NAT for the public subnet
- Step 12: Develop an Elastic IP
- Step 13: Link the Elastic to the NAT
- Step 14: For the NAT, disable source/destination checks.
- Step 15: Include NAT as a route in the initial VOC Route Table.
9. What Makes AWS VPC Stand Out from the Rest of the Private Clouds?
The following two characteristics set AWS VPC apart from others:
- It precludes the need for setting up and managing physical data centers, hardware, and/or virtual private networks when you need private network in the cloud.
- The robust security features that come with AWS VPC make it incredibly secure from security and privacy threats.
10. How Can I Monitor the Network Traffic in my Virtual Private Cloud?
To observe the traffic of your VPC, you can leverage the Amazon VPC flow logs feature.
11. How Do I Specify the Location of My Subnets?
Every time you create a subnet, you’ll need to mention the Availability Zone where it should be located. While using the VPC wizard, the wizard confirmation screen allows you to opt for an Availability Zone for the subnet.
If you’re using the CLI or API, you can choose the subnet’s Availability Zone when you begin creating the subnet. If you fail to select an Availability Zone when creating a subnet, “No Preference” option will be automatically chosen. The subnet will be set up in whichever Availability Zone is available in that region.
12. How Do the Concepts of Stateless Filtering and Stateful Filtering Differ?
Stateful Filtering detects where a request originated from and will automatically enable the response to that request to be delivered back to the originating system or computer.
For instance, a stateful filter that authorizes inbound traffic to a web server’s TCP port 80 will enable the return traffic to go through the stateful filter between the web server and the client.
The filtering device manages a state table that is capable of tracking the origin, and destination IP address ad port numbers. The only rule that the filtering device requires is to allow traffic inbound on TCP port 80 to the web server.
In contrast, stateless filtering merely inspects the destination port and IP address, regardless of whether the traffic is a reply to a request or a new request itself. For the aforementioned example, this filtering device will require two rules:
- Allow outbound traffic from the web server
- Allow traffic inbound on TCP port 80 to the web server
AWS VPC Interview Questions for experienced
AWS VPC Interview Questions Based on Scenarios
You may also like to explore below interview questions on AWS.
- AWS IAM Interview Questions And Answers
- AWS S3 Interview Questions And Answers
- AWS EC2 Interview Questions And Answers
Conclusion
Whether you have an interview at one of the companies that use AWS services or at Amazon itself, it’s important to prepare for the latest AWS VPC-related questions.
We’ve tried to cover the most common AWS interview questions on VPC that are often asked by companies that rely heavily on AWS solutions.
To help you out, we’ll keep updating this guide with more relevant questions asked during interviews.
I am an Amazon Web Services Professional, having more than 11 years of experience in AWS and other technologies. Extensively working in various AWS tools like S3, Lambda, API, Kinesis, Load Balancers, EKS, ECS, and many more. Working as a Solution Architect and Technology Lead for Architecting and implementing the same for different clients. He provides expert solutions around the world and especially in countries like the United States, Canada, United Kingdom, Australia, New Zealand, etc. Check out the complete profile on About us.
